Oil fuel firing assemblies



Feb. 7, 1961 Filed April 7, 1958 H. E. EKLUND 2,970,640

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OIL FUEL FIRING ASSEMBLIES Filed April 7, 1958 5 Sheets-Sheet 2 HANS E. EKLUND INVENTOR BY M/wnlwmm, mil

ATTORNEYS Feb. 7, 1961 H. E. EKLUND 2,970,640

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H. E. EKLUND 2,970,640

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Hams EmLk M4 85 WW, m WM United States Patent OIL FUEL FIRING ASSEMBLIES Hans Erik Eklund, Malmo, Sweden, assignor to Aktiebolaget Ljungmans Verkstader, Malmo, Sweden, a corporation of Sweden Filed Apr. 7, 1958, Ser. No. 726,763

Claims priority, application Sweden May 5, 1957 6 Claims. (Cl. 158-363) This invention relates to an oil fuel burning assembly and has for its particular object to provide such an assembly which is improved in several respects as compared with the hitherto available types. The assembly according to the invention is primarily intended for use in connection with central heating boilers in small buildings, such as detached houses, but in a suitable embodiment it may also be employed in connection with large central heating boilers. Furthermore, the invention can be applied to assemblies of either the low pressure or the high pressure type.

An improvement gained by the invention resides in the realization of so compact a design of the entire oil fuel burner assembly that it can be placed close to the boiler, is suitable for a direct mounting on the front thereof so as to occupy but very little space in front of the boiler, and can be given a more pleasant, rounded appearance than what has generally been the case hitherto. Finally, the invention brings the improvement that the built-together main parts of the assembly form a unit which, inasmuch as it can be hung merely on a pair of horizontal bolts, is easily taken out for inspection purposes and which, particularly in low pressure assemblies, comprises a float bowl which is secured with the aid of an easily detachable coupling so as to be readily accessible for adjustment and maintenance.

The invention will be described more in detail in the following as applied to an oil burner assembly of the low pressure type shown in the accompanying drawings. In the drawings:

Fig. 1 is a vertical section of the assembly mounted in a housing, certain parts being shown in elevation;

Fig. 2 is a fragmentary view of the uppermost portion of the assembly likewise in vertical section but in another state than in Fig. l;

Fig. 3 is a side elevation of the assembly, showing its housing taken apart so that the principal configuration of the assembly parts in the housing is visible; Q

Fig. 4 is a side elevation of the lower part of the assembly with the housing shown in section;

Fig. 5 is a similar side elevation of the lower part of the assembly with the housing and oil and air conveying means and oil atomizing nozzle means shown in section;

Fig.- 6 is a vertical section of certain parts of the assembly for a clearer showing of the passages in the assembly, the section being taken on line VI-VI in Fig. 5;

Fig. 7 is a horizontal section on line AA in Fig. 6.

The oil burner assembly as a whole is built into a housing formed by a back portion 1 and a front portion 2 (see Fig. 3) which are sealingly connected together, the back portion being adapted for direct mounting on the front of a boiler.

parts of the assembly whiclrare built together to a unit.

Said unit comprises a supporting block 6 which on either Secured to the back portion 1 is a holder 3 having two upwardly and forwardly directed side has a straight horizontal bored thickened portion 7 which is adapted to be passed onto one bolt 5 and be clamped as shown in Fig. 4, with the interposition of end bushes 8, by means of a tubular spacing member 9 and a nut 10. The bolts 5 also serve to secure the front portion 2 of the housing by means of cap nuts 11 (Fig. 4).

The supporting block 6 has a horizontal lower part in which a vertical shaft 12 is mounted for rotation. This shaft is common to a suction pump 13 which sucks oil to the assembly from the storage container, a feed pump 14 for the oil, a mixing pump 15 receiving the oil from the feed pump and mixing it with combustion air, a fan wheel 16 sucking in the combustion air, and an electric motor 17 driving the said three pumps and the fan wheel. The pumps 13, 14 and 15 which are of a known design are arranged axially below each other beneath the supporting block 6 in a common pump housing 18 which is screwed to the underside of the supporting block and in which the lower end of the shaft 12 is mounted. At the underside of the housing 18 a closed float vessel 19 is secured by means of an easily detachable coupling which, as shown in Fig. 4, consists of a 'U-shaped clamping member 20 which is pivotally mounted on the sides of the float vessel and which has hooked ends 21 engaging stationary pins 22 on the sides of the housing 18. The float Vessel 19 is composed of a bottom or bowl portion 19a and a top portion or cover 23, the latter abutting against the bottom of the housing 13. Secured to the upper end of the shaft 12 is the fan wheel 16 and arranged below said wheel but above the bottom part'of the supporting block 6 is the motor 17 which consists of a stator 24, without any envelope, which is screwed to the supporting block 6, and a rotor 25 secured to said shaft 12.

A stationary cylindrical fan shell 26 is secured on top of the stator 24 and has one upper end wall 27 provided with a number of apertures 28 located in a circle around the centre, said fan shell being open at the lower end both towards the motor 17 and towards the space around the motor in the housing 1, 2. The shell 26 has a peripheral flange 29 which forms an extension of the end wall 27 and is sealingly inserted in a packing 3ft e.g. of rubber which is secured around the housing 1, 2 on the inner side thereof so that the only communication between the interior of the housing and the atmosphere is through the apertures 28.

A disk or flat ring 31 is arranged on the end wall 27 of the shell 26 and is vertically movable between a position in which it covers the apertures 28,. as is shown in Fig. 1, and a raised position in which the apertures are uncovered, as shown in Figs. 2 and 5. The end wall 27 thus forms the stationary part, and the disk or ring 31 the movable part of a shut-off valve which is mounted in the entrance for the air through the upper end of the housing 1, 2 to the fan wheel 16. As a means for raising and lowering the disk 31 an expansion bag 32 is provided between the underside of the disk 31 and the upper side of the central portion ofthe end wall 27, said ex J pansion bag being formed by two rubber membranes which'are clamped, one tolthe end wall and the other to the disk 31, and which are united along their common periphery. The expansion bag 32 is in communication through a nipple 33 in the end wall with a conduit 34 through which it can be supplied with oil and air under the pressure generated by the mixing pump 15, as will be described later on, and thus be expanded so that the valve disk 31 is raised into the open position according to Fig. 2. This open position is adjustable by means of a set screw 35 which is screwed into the end wall 27 and the lower endof whichforms an abutment for theexpansion bag 32, thereby limiting its expansion.

The outlet of the mixing pump 15 is connected by a passage 36 in the shell 26 to the interior of the float ves- 3 sel 19 so that the latter receives the oil-air mixture from the pump. From the passage 36 extends a branch passage 37 to which the said conduit 34 to the expansion bag 32 is connected.

The two concentric tubes 38 and 39 are connected to the .float vessel 19 at the back thereof and extend horizontally out through the back of the housing 1, 2 carrying the conventional burner nozzle 52 at their remote ends. Within the vessel 19 the inner tube 38 is connected to an oil supply tube 40 which is immersed into the oil on the bottom of the bowl 1% and the inlet of which is controlled by a valve 42 adjusted by the float 41. The outer tube 39 is in communication with the upper space in the vessel 19, which is filled with air and finely dispersed oil. To the rear wall of the back por tion 1 of the housing ll, 2, a tube 43 of large diameter, which concentrically surrounds the burner tubes 38 and 39, extends horizontally backwards, forming together with the latter what is conventionally termed a burner head (cf. Figs. 3 and 4) adapted to project into the boiler. As will be understood, the tube 43 will deliver a blast of air which is drawn into the housing 1, 2 by the fan wheel 16 to the flame at the burner nozzle 52 as secondary combustion air.

As will be apparent from the above description, the unit hung on the bolts 5 and which can be detached from said bolts and removed in its entirety from the housing 1, 2, consists of a number'of interconnected stationary parts lying axially in a vertical row, viz. the supporting block 6, the pump housing 18, the float vessel 19, the stator 24 and the fan shell 26 as well as of the vertical shaft 12 rotatable therein with the means fixedly secured thereon, i.e. the pumps 13, 14 and 15, the fan wheel 16, the rotor 25 andthe valve disk 31. At the removal of this unit the tubes 38 and 39 and the burner nozzle are also carried along and the nozzle is thus easily accessible for inspection and adjustment. Besides, the float vessel 19, with the tubes 38 and 39 and the nozzle can be separately removed, after disengagement of the coupling see-22, for inspection of the float valve 42.

In addition to the above-mentioned removable assembly unit, the housing ll, 2 contains the usual ignition transformer 44 and an oil meter 45. As diagrammatic-ally shown in Fig. l, the latter is inserted in a connecting line 46 between the feed pump 14 and a mixing pump 15 to measure the oil consumption of the assembly. Also, the housing contains a contact block 53 to provide for the connection of the electrical wiring of the burner assembly to a current supply in an easily accessible way.

When the assembly is in operation, oil is sucked from the shortage tank (not shown) through a conduit 47 by the suction'pump 3d and is delivered by said pump to the feed pump 14 in an amount per unit of time that can be determined by adjustment of the pump it with the aid of control means 4%. The excess oil flows through a conduit 49 back to the tank. From the feed pump 14 the oil is passed through said conduit 46 via the oil .meter 45 into a space 54 above the bottom portion of the supporting block 6 and there meets air which is sucked in by the fan Wheel 16 through :the valve 27, 31 which is now-open, and, after passing as cooling air through the motor 17, the air enters the space Stl. From the latter the oil and the air together flow into the mixing pump 15 where the oil is finely dispersed and intimately mixed with the air, the pressure of which can be adjusted by control rneans 51. The mixture is delivered by said pump to the float vessel 19 where pure oil collects on the bottom and a mixture of air and finely dispersed oil in the" Theoil-air mixture also fills the conspace above it. duit 34 and the expansion bag 32 and holds the latter I expanded by thepressure generated by the mixing pump ZlSso that the valve '27, 33. is held-open, as has been supfposed. The oil and the oil-air mixture are driven from the float vessel through the burner tubes 38 and 39,

4 pump, the accompanying air serving as primary combustion air.

When the assembly stops, the pressure on the pressure side of the mixing pump 15 sinks, whereby the expansion bag 32 collapses and permits the valve disk 31 to shut off the inlet for the air. When the assembly starts again the mixing pump immediately begins to pump oil into the float vessel (together with the air already existing inside the valve 27, 31) so that the pressure rises and the valve 27, 31 is opened with certainty, whereupon normal function occurs again.

While the invention has been described by way of example in a preferred embodiment, it is understood that it is not limited thereto. It can be applied also to various other embodiments and types of assemblies. As has been mentioned in the introduction, use can be made of the invention also in high'pressure assemblies, in which case only a single oil pump is employed.

What I claim and desire to secure by Letters Patent is:

1. In an oil burner assembly, a housing including a fixed back portion and a removable front cover portion, a horizontal air blast tube extending from said fixed back portion at the rear thereof, oil and air conveying means and oil atomizing nozzle means positioned within said tube, fixed guide support means within said housing protruding from said fixed back portion thereof, a mounting block slidably supported on said guide support means to be withdrawable in a forward direction, blowing means for drawing air into said housing and delivering it to said air blast tube and said nozzle means, pump means for propelling fuel oil from a'supply to said nozzle means, an electric motor connected to said blowing means and said pump means, said blowing means, said pump means and said motor being supported on said mounting block in axial alignment, with said motor positioned near said block and said blowing means positioned adjacent said motor remote from said block, and forming together with said block a structural unit having its axis at right angles to the direction of withdrawal of said block, said oil and air conveying means and said oil atomizing nozzle means being mounted on said unit, means for peripherally sealing said unit to said housing adjacent said blowing means for forming a closed space in said housing inside of said sealing means, said housing being open to the atmosphere outside of said sealing means to admit air to the suction side of said blowing means, and means on said guide support means for releasably clamping said'unit on said guide support means.

2. In an oil burner assembly, a housing including a fixed back portion and a removable front cover portion, a horizontal air blasttube extending from said fixed back portion of said housing at the rear thereof, oil and air conveying means and oilatomizing nozzle means position'ed within said tube, fixed guide support means within said housing protruding from said fixed back portion thereof, a mounting block slidabl'y' supported on said guide support means to be withdrawable in a forward drrectron, blowing means for drawing air into said housing and delivering it'to said air blast tube and said nozzle means and comprising a stationary shell and a rotatable blower wheel with n said shell, pump means for propelling'fuel oil from a supply to said nozzle means and comprising a body member clamped to .said block and a pump rotor member within said body member, an electric motor foroperating said blowing means and said pump means and comprising a stator member clamped to said block at the opposite'side thereof to said pump means and having the stationary shell of said blowing means clamped to it and a rotor member including an axle mounted in saidblock at right angles to the direction of withdrawal of said block and carrying said, blower 7 wheel and said pump rotor member, said blowingmeans,

pump and motor and'said blocktogether forming a structural unit, said oil and,air conveyingrneans and said oil atomizing nozzle means being mounted on said unit, and

means on said guide support means for releasably clamping said structural unit on said guidesupport means.

3. In an oil burner assembly, a housing including a fixed back portion and a removable front cover portion, a horizontal air blast tube extending from said fixed back portion at the rear thereof, oil and air conveying means and oil atomizing nozzle means positioned within said tube, fixed guide support means within said housing protruding from said fixed back portion thereof, a mounting block slidably supported on said guide support means to be withdrawable in a forward direction, blowing means for drawing air into said housing and delivering it to said air blast tube and said nozzle means and comprising a stationary shell and a rotatable blower wheel within said shell, pump means for propelling fuel oil from a supply to said nozzle means and comprising a body member clamped to said block and a pump rotor member within said body member, an electric motor for operating said blowing means and said pump means and comprising a statpr member clamped to said block at the opposite side thereof to said pump means and having the stationary shell of said blowing means clamped to it and a rotor member including an axle mounted in said block at right angles to the direction of withdrawal of said block and carrying also said blower wheel and said pump rotor member, said blowing means, pump and motor and said block together forming a structural unit, said oil and air conveying means and said oil atomizing nozzle means being mounted on said unit, means for peripherally sealing said stationary shell to said housing to form a closed space in said housing inside of said sealing means, said housing being open to the atmosphere outside of said sealing means to admit air to the suction side of said blowing means, said shell having the edge adjacent said stator spaced from said stator to folm a path for the air from said blowing means into said closed space and to said air blast tube, and said motor having another path therethrough for the air from said blowing means to said nozzle means to cause this air to act as a cooling medium for said motor before arriving at said nozzle means, and means on said guide support means for releasably clamping said structural unit on said guide support means.

4. In an oil burner assembly, a housing including a fixed, back portion and a removable front cover portion, a horizontal air blast tube extending from said fixed back porticpn at the rear thereof, oil and air conveying means and oil atomizing nozzle means positioned within said tube, fixed guide support means within said housing protruding from said fixed back portion thereof, a mounting block slidably supported on said guide support means to be withdrawable in a forward direction, blowing means for drawing air into air blast tube and said nozzle means, pump means for propelling fuel oil from a supply to said nozzle means, an electric motor connected to said blowing means and said pump means, said blowing means, said pump means and said motor being supported by said mounting block in axial alignment, with said motor positioned near said block, and forming together with said block a structural unit having its axis at right angles to the direction of withdrawal of said block, and means on said guide support means for'releasably clamping said unit on said guide said housing and delivering it to said support means, said oiland air conveying means and said oil atomizing nozzle means being mounted on said unit and withdrawable therewith on releasing said clamping means.

5. In an oil burner assembly, a housing including a fixed back portion and a removable front cover portion, a horizontal air blast tube extending from said fixed back portion at the rear thereof, oil and air conveying means and oil atomizing nozzle means positioned within said tube, fixed guide support means within said housing protruding from said fixed back portion thereof, a mounting block slidably supported on said guide support means to be withdrawable in a forward direction, blowing means for drawing air into said housing and delivering it to said air blast tube and said nozzle means, pump means for propelling fuel oil from a supply to said nozzle means, an electric motor for operating said blowing means and said pump means, said blowing means, said pump means and said motor being supported by said mounting block in axial alignment, with said motor positioned near said block, and forming together with said block a structural unit having its axis at right angles to the direction of withdrawal of said block, means on said guide support means for releasably clamping said unit on said guide support means, and a float vessel attached to said unit and communicating with said pump means to receive an airoil mixture therefrom, said oil and air conveying means and said oil atomizing nozzle means being mounted on said float vessel and withdrawable together with said unit and said float vessel on releasing said clamping means.

6. In an oil burner assembly, a housing including a fixed back portion and a removable front cover portion, a horizontal air blast tube extending from said fixed back portion at the rear thereof, oil and air conveying means and oil atomizing nozzle means positioned within said tube, fixed guide support means within said housing protruding from said fixed back portion thereof, a mounting block slidably supported on said guide support means to be withdrawable in a forward direction, blowing means for drawing air into said housing and delivering it to said air blast tube and said nozzle means, pump means for propelling fuel oil from a supply to said nozzle means, an electric motor for operating said blowing means and said pump means, said blowing means, said pump means andsaid motor being supported by said mounting block in axial alignment, with said motor positioned near said block, and forming together with said block a structural unit having its axis at right angles to the direction of withdrawal of said block, first clamping means on said guide support means for clamping said unit on said guide support means, a float vessel associated with said unit and communicating with said pump means to receive an airoil mixture therefrom, and second clamping means for releasably clamping said float vessel to said unit to permit the withdrawal of said float vessel separate from said unit, said oil and air conveying means and said oil atomizing nozzle being mounted on said float vessel to be withdrawable together with said unit and said fioat'vessel on releasing said first clamping means and together with said float vessel alone on releasing said second clamping means.

References Cited in the file of this patent UNITED STATES PATENTS UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 2,970, 6 .10 February 7 1961 Hans Erik Eklund It is hereby certified that error appears in the above numbered patent requiring correction and that the sa id Letters Patent should read as corrected below. I

In the heading to the printed specification line 7 for "May 5 1957" read May 10,, 1957 Signed and sealed this 21st day of November 1961.

(SEAL) Attest:

ERNEST W. SWIDER Commissioner of Patents USCOMM-DC 

